脂质沉积性肌病的电镜诊断

Diagnosis of lipid storage myopathy by electron microscopy

目的脂质沉积性肌病是神经内科一种少见肌病,观察脂质沉积性肌病的超微结构特点,探讨电镜检查对脂质沉积性肌病的诊断价值及其与线粒体病的关系。方法对7例临床上出现肌无力的患者进行肌肉活检,取股四头肌或腓肠肌进行常规电镜标本制备,半薄切片甲苯胺蓝染色选取部位后进行超薄切片,铅、铀染色后透射电镜观察、分析。结果所有患者的肌肉活检均显示肌纤维内出现大量的脂滴,脂滴排列密集,呈串珠状分布在残存的肌丝间,存在明显脂滴融合现象。1例线粒体明显异常,出现明显的结晶样包涵体。毛细血管内皮细胞内和成纤维细胞的胞质内也能发现脂滴。1例有明显神经痛,电镜检查发现外周神经髓鞘板层分离,雪旺氏(Schwann)细胞内出现脂滴沉积。1例间质有胶原纤维增生,并可见再生肌纤维。结论脂质沉积性肌病是一组有独特超微结构特点的肌病,与线粒体异常有一定关系,电镜检查有助于该病的确诊。

t Objective To observe the ultrastructural features of lipid storage myopathy and explore the diagnostic value of electron microscopy in lipid storage myopathy and the relationship between this disease and mitochondrial myopathy. Methods Muscle biopsies were performed in 7 patients who had weakness. Quadriceps and gastrocnemins muscles were obtained from biopsy and processed with routine electron microscopic procedures. Semithin sections were made with ultramicrotome and stained with buffered toluidine blue. After the proper positions were selected, ultrathin sections were made and stained with uranyl acetate and lead citrate. A JEM 2000EX transmission electron microscope was used in observation and analysis. Results A lot of lipid droplets were found in muscle cells of all cases. Lipid droplets arranged tightly as a string of beads in the residual myofilaments and fused each other. Abnormal mitochondrias with crystalline intramitochondrial inclusion bodies were found in one case. The intracellular lipid droplets were also found in endothelium of capillaries and fibroblasts of interstitial tissue. The obvious neuralgia occurred in one case, whose electron microscopy results presented that the myelin lamellae of myelin sheath was abnormaUy widened and lipid droplets presented in some Schwann cells. Proliferation of collagen fibers and regenerating muscle cells appeared in some cases. Condusion Lipid storage myopathy is a group of myopathies with unique ultrastructural characteristics and is related with mitochondrial disorders. It is useful for definitive diagnosis of the disease to perform electron microscopy.